The parathyroid glands are four small, pea-sized glands located behind the thyroid gland in the neck. They are responsible for regulating calcium levels in the blood and bones by producing parathyroid hormone (PTH).
Despite being close to the thyroid, the parathyroid glands have a completely separate function, focusing solely on calcium and phosphorus balance rather than metabolism.
Explanation of the Parathyroid Glands’ Role in the Body
The parathyroid glands maintain calcium homeostasis, which is essential for:
✔ Bone health – Proper calcium levels prevent osteoporosis and brittle bones.
✔ Nerve function – Calcium is necessary for proper nerve signaling.
✔ Muscle contraction – Low calcium levels can lead to muscle cramps and spasms.
✔ Blood clotting & heart function – Calcium is needed for blood coagulation and steady heartbeats.
These glands release PTH when blood calcium is low and stop producing PTH when calcium is high, ensuring a stable balance.
Key Hormone Produced by the Parathyroid Glands
| Hormone | Function | Effect on the Body |
|---|---|---|
| Parathyroid Hormone (PTH) | Raises blood calcium levels by acting on bones, kidneys, and intestines. | Releases calcium from bones, increases calcium absorption in intestines, reduces calcium loss in urine. |
✔ PTH is essential for maintaining strong bones and proper nerve and muscle function.
How the Parathyroid Glands Regulate Calcium Levels
🔹 The Calcium Feedback Loop:
1️⃣ Low blood calcium detected → Parathyroid glands release PTH.
2️⃣ PTH increases calcium by:
- Releasing calcium from bones into the bloodstream.
- Increasing calcium absorption in the intestines (by activating vitamin D).
- Reducing calcium excretion through the kidneys.
3️⃣ Once calcium reaches the correct level, PTH secretion stops to prevent excess calcium buildup.
✔ This feedback system prevents both calcium deficiency and calcium overload.
Common Parathyroid Disorders & Their Symptoms
🔴 Hyperparathyroidism (Overactive Parathyroid) – Too Much PTH
❌ Excess calcium in the blood (hypercalcemia) – Leads to kidney stones, bone loss, and fatigue.
❌ Weakened bones (osteoporosis) – Calcium is pulled from bones, making them brittle.
❌ Frequent urination & kidney stones – The kidneys work harder to remove excess calcium.
❌ Mental fog & depression – High calcium can affect brain function.
🟢 Causes:
- Parathyroid tumors (benign).
- Chronic kidney disease (secondary hyperparathyroidism).
🔵 Hypoparathyroidism (Underactive Parathyroid) – Too Little PTH
❌ Low blood calcium (hypocalcemia) – Causes muscle cramps, tingling, and spasms.
❌ Weak nails, brittle hair, and dry skin – Due to poor calcium balance.
❌ Heart rhythm abnormalities – Calcium is essential for heart function.
❌ Seizures in severe cases – Very low calcium levels can affect brain function.
🟢 Causes:
- Thyroid surgery (damage to parathyroid glands).
- Autoimmune diseases.
✔ Both conditions require medical treatment to restore calcium balance.
How to Support Healthy Parathyroid Function
✅ Ensure Enough Calcium Intake 🥛 – Dairy, leafy greens, and fortified foods provide dietary calcium.
✅ Get Enough Vitamin D ☀️ – Vitamin D helps absorb calcium efficiently.
✅ Limit Phosphorus-Rich Processed Foods 🚫 – Too much phosphorus (soda, processed meats) can disrupt calcium balance.
✅ Stay Hydrated 💧 – Prevents kidney stones in people with high calcium levels.
✅ Monitor Bone Health 🦴 – Regular checkups can detect early bone loss.
✔ A balanced diet, vitamin D, and proper hydration help maintain optimal parathyroid function.
Final Takeaway
The parathyroid glands regulate calcium levels in the blood and bones by producing parathyroid hormone (PTH). Proper calcium balance is crucial for strong bones, nerve function, muscle contraction, and heart health. Disorders like hyperparathyroidism (high calcium) and hypoparathyroidism (low calcium) can cause bone weakness, kidney stones, and muscle problems. Maintaining a healthy diet, getting enough vitamin D, and monitoring calcium levels can support optimal parathyroid function.